The invention is in the field of underwater sound transmission systems. One example of such systems is an array of hydrophones arranged to receive underwater sound energy and which is directionally sensitive to the angle of arrival of an impinging sound wave. Such arrays are commonly employed in sonar systems.
In such systems of the prior art interfering noise at the hydrophones can cause clipping nonlinearities in the system, greatly degrading performance. It is known that the effect of such interference can be reduced by combining the outputs of dipole hydrophones positioned orthogonally with respect to each other in such manner that the resulting dipole pattern can be steered to achieve a null. The invention overcomes the deficiencies of the prior art by providing means for automatically computing a null position and rotating the pattern function of the combination of two dipole hydrophones to such position to minimize noise in the system.